Investigation of electrical conductivity of milk in robotic milking system and its relationship with milk somatic cell count and other quality traits

The scientific research was carried out at Lithuanian University of Health Sciences, Veterinary Academy, state enterprise “Pieno tyrimai”, as well as in dairy farms running automatic voluntary (robotic) milking systems in Lithuania. A total data set of 462574 cow milking records was assessed in the research. The objectives of this investigation were to evaluate the milk electrical conductivity indicator from robotic milking system and to assess the genetic correlation with the indices collected in a database of Lithuanian dairy cattle, to estimate heritability coefficient using multiple traits mixed linear model with permanent environment effects. The research has shown, that the electrical conductivity of milk ranged from 4.6 to 5.8 ms/cm in milk samples where somatic cell count did not exceed 200 thousand/ml and variation in electric conductivity of milk can be treated as one of the main parameters for cows’ health monitoring system. A high coefficient of heritability of electrical conductivity of milk (h2 = 0.512 ± 0.028; p < 0.001) and a very low coefficient of heritability of somatic cell count (h2 = 0.032 ± 0.014; p < 0.001) was determined. The results of the research have also revealed a positive genetic correlation of electrical conductivity with milk somatic cell count (rg = 0.332 ± 0.016; p < 0.001). Electrical conductivity of milk from robotic milking system can be introduced as an indicator of mastitis prevention in dairy cows and genetic selection based on this trait may be possible

Convection in mineral wool used as insulation for buildings

The paper considers the velocities of air movement in the ventilated air gaps of walls and focuses on pressure fields in both wall models arranged in a climatic chamber and exploited houses. The article investigates the influence of air movement on heat transfer through walls applying numerical modelling methods and conducting experiments in the climatic chamber. The thermal effects of air flows have been described with reference to the Nusselt number defined as the ratio of average convective and conductive heat fluxes and heat flux through still air

Ascertaining the influence of lacto-fermentation on changes in bovine colostrum amino and fatty acid profiles

The aim of this study was to collect samples of bovine colostrum (BCOL) from different sources (agricultural companies A, B, C, D and E) in Lithuania and to ascertain the influence of lacto-fermentation with Lactiplantibacillus plantarum strain 135 and Lacticaseibacillus paracasei strain 244 on the changes in bovine colostrum amino (AA), biogenic amine (BA), and fatty acid (FA) profiles. It was established that the source of the bovine colostrum, the used LAB, and their interaction had significant effects (p < 0.05) on AA contents; lactic acid bacteria (LAB) used for fermentation was a significant factor for aspartic acid, threonine, glycine, alanine, methionine, phenylalanine, lysine, histidine, and tyrosine; and these factor’s interaction is significant on most of the detected AA concentrations. Total BA content showed significant correlations with glutamic acid, serine, aspartic acid, valine, methionine, phenylalanine, histidine, and gamma amino-butyric acid content in bovine colostrum. Despite the differences in individual FA contents in bovine colostrum, significant differences were not found in total saturated (SFA), monounsaturated (MUFA), and polyunsaturated (PUFA) fatty acids. Finally, the utilization of bovine colostrum proved to be challenging because of the variability on its composition. These results suggest that processing bovine colostrum into value-added formulations for human consumption requires the adjustment of its composition since the primary production stage. Consequently, animal rearing should be considered in the employed bovine colostrum processing technologies.info:eu-repo/semantics/publishedVersio

The influence of natural convection on thermal properties of building enclosure with polystyrene boards/Putų polistireno plokštėmis izoliuotų pastatų sienų šiluminių savybių priklausomybė nuo natūralios konvekcijos

Building insulating materials with good insulation properties usually are porous, because they contain large amounts of air or other gas inside. The pore system can be closed, as in many cellular plastics, or open as in fibre materials. The mechanisms of heat transfer in porous material are: conduction in solid phase, radiation within material and conduction due to the gas confined in the insulation. In an open-pore material, like lightweight mineral wool, the transportation of heat can be further increased by air movement (convection) through the permeable material. Convection is impossible in a closed porous materials like polystyrene (EPS, XPS) boards. But heat losses can be increased by air movement if there are cracks between boards and other building envelope structures. The airflow velocity and direction may vary strongly due to the changing boundary condition. However, at the present time in Lithuania convection in insulating materials is considered as non-existent, when calculating heat transmission and designing building structures. Because of the lack of knowledge concerning air movement in external building structures, and how it is affecting the heat transfer, this investigation has been carried out. For research an equipment (Fig 2) was made, assigned for exploring both vertical and horizontal structures (height 2100 mm, width 1100 mm and thickness up to 300 mm). For reducing heat losses through the sides up to minimum, an equipment was built from slabs (thickness 150 mm). As the hot side of equipment gypsum board was applied to the surface of which 8 heat flow sensors and 9 thermocouples were attached. For maintaining constant and isothermal temperature of the surface of this partition (Θi, =+20°C), heating elements and ventilators were mounted inside the equipment. The cold surface of the equipment was of the same construction as the warm one only with the regulated slide valve with an area of 0,02 m2. It allows exploring the so-called not-ventilated structures. During the test, temperature was measured at different places and depths. The research was performed on the foam polystyrene plates of 3×50 mm of thickness with 3–5 mm air gaps. Measurements were conducted in the following sequence: • Two basic measurements of closed structure were performed for constant values of temperatures Θe=0°C and Θe=10°C. In this case the structure was held horizontally and heat flow was directed from top to bottom. Therefore it could be assumed that heat was transferred by conduction and radiation. • Measurements of the closed structure were performed on the equipment being in vertical position and for external temperature Θe=0°C and Θe=10°C. • Measurements of the opened structure. The measurement carried out for the same external environment conditions, the ventilating orifice being opened. The results of laboratory experiments allowed to assess the heat losses of the enclosure being arranged in the form of wall with air gaps applying foam polystyrene slabs. Different types of structures being investigated are shown in Fig 1. The Nu numbers for closed and ventilated structures are presented in Figs 8 and 9. The research results could be applied to enclosures with hard type insulation too. Although the natural convection does not occur inside the ideal material, but it takes place inside enclosure with air gaps. Thus, actual U-value depends on structural solutions and air tightness on building envelope. If wind barrier is permeable, then air filtration through the structure may cause even critical values for heat losses. First Published Online: 26 Jul 201

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Vytauto Didžiojo universitetasŽemės ūkio akademij

Piktžolės: klasifikacija ir pažinimas

Vytauto Didžiojo universitetasŽemės ūkio akademij

Žolinių pašarų konservantų ir siloso cheminė sudėtis, maistinė vertė ir virškinamumas

Santr. liet., anglBibliogr.: p.99-100 (12 pavad.)Vytauto Didžiojo universitetasŽemės ūkio akademij

Zootechninė pašarų analizė ir jų energetinė vertė : laboratorinių darbų metodiniai patarimai Agronomijos fakulteto magistrantams ir doktorantams

Bibliogr.: p. 43Vytauto Didžiojo universitetasŽemės ūkio akademij

Tyrimų duomenys apie maisto medžiagų kiekius silose, virškinamumą ir energinę pašarinę vertę

Santr. vokBibliogr.: p. 52 (8 pavad.)Vytauto Didžiojo universitetasŽemės ūkio akademij

Sauja piktžolių kukurūzų siloso nepagadins

Vytauto Didžiojo universitetasŽemės ūkio akademij